Different species of invertebrates reproduce in different ways, including through sexual intercourse, asexual clonal fission or releasing free spawning gametes. Some species of invertebrates are hermaphroditic, meaning they have both male and female sexual organs, while other species actually change their sex.
There are millions of species of invertebrates, which can be found on land and in water. Both the octopus and the squid are examples of marine invertebrates that use sexual intercourse to reproduce, while many other types of mollusks reproduce by simultaneously spawning huge amounts of eggs and sperm into the water.
Although hermaphroditic invertebrates, such as nematodes, carry both sex organs, they still require another individual to reproduce. On the other hand, there are many asexual invertebrates that generally reproduce by splitting, which results in an identical clone of the original organism.
Invertebrates are classified as any species of animal without a backbone. This group is thought to make up approximately 97 percent of all animal species on the planet. Due to the huge number of different phyla and species, the term "invertebrate" is not very useful in animal classification. In fact, some groups of invertebrates have more in common with vertebrates than they do other invertebrates.